Therapeutic Drug Monitoring Assays from ARK and Dialab
Clinical Importance of Methotrexate Monitoring
Methotrexate (MTX) is one of the few antimetabolite drugs routinely monitored in most treatment centres and is used in the treatment of certain neoplastic diseases, severe psoriasis and adult rheumatoid arthritis. Disruption of DNA synthesis and 7-OH MTX metabolism mean that MTX therapy has potential for serious toxicity and patients should be closely monitored to enable prompt detection of toxic effects.
Leucovorin (also known as folinic acid) is a synthetic substrate for DHFR and is frequently used in conjunction with MTX as a rescue therapy as it enables resumption of DNA synthesis in normal cells.
Accurate measurement of Methotrexate concentrations are important, clinical guidelines for leucovorin (folinic acid) rescue typically recommend that intravenous administration of leucovorin until MTX concentration fall below 0.05µmol/L
The Methotrexate Assay Overview
The ARK Diagnostics Methotrexate (MTX) immunoassay provides accurate quantitative determination of methotrexate concentrations in both serum and plasma.
This sensitive assay can measure very low concentrations (0.05µmol/L) of MTX which are of key clinical importance and the method does not react with 7-hydroxymethotrexate, the major metabolite of methotrexate.
The ready-to-use, liquid reagents can be used directly from the refrigerator and pack sizes have been designed to match the most typical laboratory workloads, thereby maximising reagent use and minimising waste. The ARK CE Marked MTX reagents are suitable for use on automated clinical chemistry analysers and a number of instrument applications are available for this kit including Roche Cobas®, Abbott ARCHITECT® and Siemens ADVIA®.